In a conventional ferroelectric memory, a tungsten (W) plug is mainly used to connect between wiring layers, and an aluminum (Al) wiring is used as wiring.
Although miniaturization has been requested recently, the miniaturization of a ferroelectric memory using the W plug and the Al wiring has limitation from the view point of manufacturing technologies, interlayer capacities and the like.
Patent Document 1
Japanese Patent Application Laid-open No. 2001-284448
Patent Document 2
Japanese Patent Application Laid-open No. 2000-82684